[PATCH v2 2/5] loop: Factor out configuring loop from status

From: Martijn Coenen
Date: Wed Apr 22 2020 - 06:56:10 EST


Factor out this code into a separate function, so it can be reused by
other code more easily.

Signed-off-by: Martijn Coenen <maco@xxxxxxxxxxx>
---
drivers/block/loop.c | 117 +++++++++++++++++++++++++------------------
1 file changed, 67 insertions(+), 50 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 4f5c765c73d8..3f8051d3115e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1275,13 +1275,78 @@ static int loop_clr_fd(struct loop_device *lo)
return __loop_clr_fd(lo, false);
}

+/**
+ * loop_set_status_from_info - configure device from loop_info
+ * @lo: struct loop_device to configure
+ * @info: struct loop_info64 to configure the device with
+ *
+ * Configures the loop device parameters according to the passed
+ * in loop_info64 configuration.
+ */
static int
-loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
+loop_set_status_from_info(struct loop_device *lo,
+ const struct loop_info64 *info)
{
int err;
struct loop_func_table *xfer;
kuid_t uid = current_uid();
+
+ if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE)
+ return -EINVAL;
+
+ err = loop_release_xfer(lo);
+ if (err)
+ return err;
+
+ if (info->lo_encrypt_type) {
+ unsigned int type = info->lo_encrypt_type;
+
+ if (type >= MAX_LO_CRYPT)
+ return -EINVAL;
+ xfer = xfer_funcs[type];
+ if (xfer == NULL)
+ return -EINVAL;
+ } else
+ xfer = NULL;
+
+ err = loop_init_xfer(lo, xfer, info);
+ if (err)
+ return err;
+
+ lo->lo_offset = info->lo_offset;
+ lo->lo_sizelimit = info->lo_sizelimit;
+ memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
+ memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
+ lo->lo_file_name[LO_NAME_SIZE-1] = 0;
+ lo->lo_crypt_name[LO_NAME_SIZE-1] = 0;
+
+ if (!xfer)
+ xfer = &none_funcs;
+ lo->transfer = xfer->transfer;
+ lo->ioctl = xfer->ioctl;
+
+ if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) !=
+ (info->lo_flags & LO_FLAGS_AUTOCLEAR))
+ lo->lo_flags ^= LO_FLAGS_AUTOCLEAR;
+
+ lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
+ lo->lo_init[0] = info->lo_init[0];
+ lo->lo_init[1] = info->lo_init[1];
+ if (info->lo_encrypt_key_size) {
+ memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
+ info->lo_encrypt_key_size);
+ lo->lo_key_owner = uid;
+ }
+
+ return 0;
+}
+
+static int
+loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
+{
+ int err;
struct block_device *bdev;
+ kuid_t uid = current_uid();
bool partscan = false;
bool size_changed = false;
loff_t validated_size;
@@ -1299,10 +1364,6 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
err = -ENXIO;
goto out_unlock;
}
- if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) {
- err = -EINVAL;
- goto out_unlock;
- }

if (lo->lo_offset != info->lo_offset ||
lo->lo_sizelimit != info->lo_sizelimit) {
@@ -1330,54 +1391,10 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
goto out_unfreeze;
}

- err = loop_release_xfer(lo);
+ err = loop_set_status_from_info(lo, info);
if (err)
goto out_unfreeze;

- if (info->lo_encrypt_type) {
- unsigned int type = info->lo_encrypt_type;
-
- if (type >= MAX_LO_CRYPT) {
- err = -EINVAL;
- goto out_unfreeze;
- }
- xfer = xfer_funcs[type];
- if (xfer == NULL) {
- err = -EINVAL;
- goto out_unfreeze;
- }
- } else
- xfer = NULL;
-
- err = loop_init_xfer(lo, xfer, info);
- if (err)
- goto out_unfreeze;
-
- lo->lo_offset = info->lo_offset;
- lo->lo_sizelimit = info->lo_sizelimit;
- memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE);
- memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE);
- lo->lo_file_name[LO_NAME_SIZE-1] = 0;
- lo->lo_crypt_name[LO_NAME_SIZE-1] = 0;
-
- if (!xfer)
- xfer = &none_funcs;
- lo->transfer = xfer->transfer;
- lo->ioctl = xfer->ioctl;
-
- if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) !=
- (info->lo_flags & LO_FLAGS_AUTOCLEAR))
- lo->lo_flags ^= LO_FLAGS_AUTOCLEAR;
-
- lo->lo_encrypt_key_size = info->lo_encrypt_key_size;
- lo->lo_init[0] = info->lo_init[0];
- lo->lo_init[1] = info->lo_init[1];
- if (info->lo_encrypt_key_size) {
- memcpy(lo->lo_encrypt_key, info->lo_encrypt_key,
- info->lo_encrypt_key_size);
- lo->lo_key_owner = uid;
- }
-
if (size_changed)
loop_set_size(lo, validated_size);

--
2.26.2.303.gf8c07b1a785-goog